Rolling device and method for the operation thereof

ABSTRACT

The invention relates to a rolling device ( 1 ) comprising at least two working rollers ( 2, 3 ) and a roll gap ( 4 ) between the working rollers ( 2, 3 ) for guiding through and rolling a rolling stock ( 5 ) such as, for example, a strip ( 6 ) preferably of metal and optionally an arrangement of support rollers ( 7, 8 ), wherein furthermore at least one measuring device ( 11 ) is provided for measuring a backslip of the rolling material of the rolling stock in front of the roll gap ( 4 ), wherein furthermore a control or regulating unit ( 13 ) is provided which drives control members for adjusting the flatness of the rolling stock on the basis of the signals of the measuring device ( 11 ).

TECHNICAL FIELD

The invention relates to a rolling device according to the preamble of claim 1 and a method for operation thereof according to claim 5.

PRIOR ART

Rolling devices have been known for a long time in the prior art. In this context, for example, such rolling devices are known in which a pair of working rollers is acted upon by at least two support rollers which are larger compared to the working rollers to absorb the rolling forces. In such rolling devices, it is furthermore known that the flatness of the rolled material can vary, whereby a backward slip of material can occur directly in front of the rolling gap between the working rollers. If the backward slip of material cannot be compensated in good time and sufficiently accurately, non-uniformities occur in the flatness of the rolled material, which leads to loss of quality of the rolled material and has the result that the rolled material is possibly completely unsuitable for some applications.

Rolling devices are known in the prior art in which flatness measurements are carried out by means of tension rollers to determine the tensile stress distribution. However, such tension rollers are typically located far away from the working rollers so that the backward slip of material in front of the roll gap cannot thereby be reliably determined. Such a rolling device has become known, for example, from EP 0 108 379 B1. This document furthermore discloses sensors for measuring the thickness profiles, wherein these sensors also determine the thickness profile far away from the roll gap. The backslip of material also cannot be reliably detected thereby.

DE 27 43 130 discloses a rolling device with thickness measuring devices in front of and behind the roll gap, whereby a predefinable thickness tolerance can thereby be achieved. However, the material backslip effect also cannot be eliminated thereby because the sensors are again also arranged far away from the roll gap. In addition, a local thickness deviation can only be meaningful in conjunction with a precise profile reference. Any flatness can therefore not be sufficiently qualified.

Other rolling devices only measure the flatness at a further distance behind the roll gap, which has the result that the results are used for regulating the flatness by flatness control elements. However, misadjustments of the mill stand do not always have sufficient influence on the outlet-side measurements or as a result of the delay thereby caused, it cannot respond sufficiently rapidly to profile or flatness variations so that the determined flatness deviations can no longer be corrected because they have already formed behind the roll gap.

DESCRIPTION OF THE INVENTION, OBJECT, SOLUTION, ADVANTAGES

It is the object of the present invention to provide a rolling device with a measuring device and a method therefor in which a material backslip is reliably identified and as a result, a regulation/control can be carried out to avoid flatness deficiencies thereby caused extending as far as unstable rolling states (sucking, overlapping, and so on).

According to the invention, the object is achieved with regard to the rolling device by a rolling device according to the features of claim 1 comprising a rolling device having at least two working rollers and a roll gap between the working rollers for guiding through and rolling a rolling stock such as, for example, a strip preferably of metal, and optionally an arrangement of support rollers, wherein furthermore at least one measuring device is provided for measuring a backslip of the rolling material of the rolling stock in front of the roll gap, wherein furthermore a control or regulating unit is provided which drives control members for adjusting the flatness of the rolling stock on the basis of the signals of the measuring device.

In this context, it is advantageous if a flatness measuring device is furthermore provided after the roll gap, which device likewise provides signals for the control and regulating unit, whereupon these drive the control members for adjusting the flatness of the rolling stock in response to the signals of the measuring device and the flatness measuring device.

It is also expedient if a control member for adjusting the flatness of the rolling stock is a control member for adjusting the inclination of the working rollers and/or the intermediate rollers and/or the support rollers, the flexure of the working rollers and/or the intermediate rollers and/or the support rollers, the axial displacement of the working rollers and/or the intermediate rollers, for example, within the framework of a continuously variable crown (CVC) displacement, a minimal quantity lubrication and/or a temperature control or temperature regulations of the strip and/or the working rollers. As a result, the desired flatness can preferably be influenced and adjusted.

In this context, it is preferably advantageous if the at least one measuring device for measuring the backslip of the rolling material of the rolling stock before the roll gap is an optically or mechanically measuring device.

According to the invention, the object is achieved with regard to the method by a method for operating a rolling device according to claim 5. The advantages of this method correspond to the advantages specified above with reference to the device.

It is also expedient if the at least one measuring device for measuring a backslip of the rolling material of the rolling stock before the roll gap optically or mechanically detects the backslip.

Advantageous further developments are described in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is explained hereinafter in detail on the basis of an exemplary embodiment with reference to the drawings. In the figures:

FIG. 1 shows a schematic diagram of a rolling device with measuring device.

PREFERRED EMBODIMENT OF THE INVENTION

FIG. 1 shows schematically a rolling device 1 comprising two working rollers 2, 3 between which a roll gap 4 is provided and between which a rolling stock 5 such as, for example, a strip 6 or metal strips such as in particular a steel strip is rolled. In this case, the working rollers 2, 3 are each advantageously acted upon with support rollers 7, 8 in a known manner. When the strip 6 runs as rolling stock in the rolling direction 9 through the roll gap 4, a material backslip 10 can occur in the immediate vicinity of the roll gap 4 and in the rolling direction in front of the roll gap 4, which backslip leads to deformations of the rolling stock and therefore causes flatness deficiencies of the rolling stock. The backslip occurs because at least temporarily, more material of the rolling stock per unit time is transported or pressed in front of the roll gap that can be rolled and can pass through the roll gap during the same unit time. The backslip occurs in areas of local drop in strip tension.

The device 1 furthermore comprises at least one measuring device 11 or at least one sensor which detects a material backslip 10 at the strip inlet of the roll gap. This at least one measuring device 11 is a preferably mechanically measuring or contactless measuring sensor. The contactless measuring sensor is preferably an optically measuring sensor which optically detects the partly only local material backslip 10. The backslip in the form of a local overreduction is visible as a decrease in strip tension in these areas extending as far as waviness in front of the roll gap and is detectable for the measuring device.

The sensor or the measuring device 11 is disposed on the inlet side of the roll gap 4 and preferably detects the material backslip 10 near the roll gap 4 or in the immediate vicinity of the roll gap 4, for example, as a result of a surface variation of the rolling stock 5 such as the strip 6. In this case, the sensor is designed in such a manner that the measurement of the material backslip in front of the roll gap is carried out approximately in an area of one metre or less in front of the roll gap, wherein preferably a measurement of the material backslip in the area of about 200 to 300 mm in front of the roll gap is detected.

On the outlet side after the roll gap 4, when viewed in the rolling direction, there is preferably provided a flatness measuring device such as a flatness measuring roller 12, which detects the flatness of the strip 6 behind the rolling device 1 with the roll gap 4.

The signals of the sensor 11 for measurement of the backslip or the signals of the sensor 11 for measurement of the backslip and the flatness measuring device 12 are supplied to a control or regulating unit 13 which, with reference to the available input data, delivers at least one trigger signal 14 or a plurality of trigger signals for the control members 15, 16, 17, 18 and 19 such as flatness control members of the rolling arrangement by which means the control members 15, 16, 17, 18 and 19 are triggered to regulate or control the flatness of the rolling stock.

The signals of the sensors 10 and 11 are supplied to the control or regulating unit 13, wherein a weighting can be carried out between the two sensors or their signals, which in each case can be acted upon by a pre-selectable additive addend and a multiplicative factor and/or individually or both signals can be acted upon with delay members and/or acted upon with filters.

By detecting the backslip 10 before the roll gap 4 and/or the backslip 10 before the roll gap 4 and the flatness after the roll gap, a stable strip running can be achieved under stable rolling conditions wherein an intervention can be made promptly if a backslip 10 of the material of the rolling stock to be rolled is detected in front of the roll gap 4. In this case, promptly preferably means that the adjustment or control takes place in real time, that is without a large time delay, i.e. in the range of about 1 second or less, down to the range of fractions of a second time delay. At a strip speed of 60 m/min, a run of 300 mm can take place in 0.3 seconds so that a rapid feedback in the range of tenths of a second or less is advantageous to correct the material backslip in front of the roll gap. By this means a rapid control intervention or adjustment intervention can be undertaken in the event of varying strip profile, with varying flatness for example at the beginning of the strip, at the strip end or at a weld seam.

The control members 15 to 19 are preferably control members for adjusting the inclination of the working rollers 2, 3 and/or the support rollers 7, 8, the flexure of the work rollers 2, 3 and/or intermediate rollers (sexto design) and/or the support rollers 7, 8, the axial displacement of the working rollers 2, 3 and/or intermediate rollers (sexto design) within the framework of a so-called continuously variable crown (CVC) displacements, a minimal quantity lubrication or a temperature control or temperature regulation of the strip and/or the working rollers.

REFERENCE LIST

-   1 Rolling device -   2 Working roller -   3 Working roller -   4 Roll gap -   5 Rolling stock -   6 Strip -   7 Support roller -   8 Support roller -   9 Rolling direction -   10 Material backslip -   11 Measuring device -   12 Flatness measuring roller -   13 Control or regulating unit -   14 Trigger signal -   15 Control member -   16 Control member -   17 Control member -   18 Control member -   19 Control member 

1. A rolling device (1) comprising at least two working rollers (2, 3) and a roll gap (4) between the working rollers (2, 3) for guiding through and rolling a rolling stock (5) such as, for example, a strip (6) preferably of metal and optionally an arrangement of support rollers (7, 8), characterized in that furthermore at least one measuring device (11) is provided for measuring a backslip of the rolling material of the rolling stock in front of the roll gap (4), wherein furthermore a control or regulating unit (13) is provided which drives control members for adjusting the flatness of the rolling stock on the basis of the signals of the measuring device (11).
 2. The rolling device (1) according to claim 1, characterized in that a flatness measuring device (12) is furthermore provided after the roll gap, which device provides signals for the control and regulating unit (13), whereupon these drive the control members (15, 16, 17, 18, 19) for adjusting the flatness of the rolling stock in response to the signals of the measuring device (11) and the flatness measuring device (12).
 3. The rolling device (1) according to claim 1, characterized in that the control member for adjusting the flatness of the rolling stock is a control member for adjusting the inclination of the working rollers (2, 3) and/or the support rollers (7, 8), the flexure of the working rollers and/or the intermediate rollers (2, 3) and/or the support rollers (7, 8), the axial displacement of the working rollers (2, 3) and/or the intermediate rollers (2, 3) within the framework of a continuously variable crown (CVC) displacement, a minimal quantity lubrication and/or a temperature control or temperature regulations of the strip and/or the working rollers.
 4. The rolling device according to claim 1, characterized in that at least one measuring device (11) for measuring a backslip of the rolling material of the rolling stock before the roll gap (4) is an optically or mechanically measuring device.
 5. A method for operating a rolling device (1) comprising at least two working rollers (2, 3) and a roll gap (4) between the working rollers (2, 3) for guiding through and rolling a rolling stock (5) such as, for example, a strip (6) preferably of metal, characterised by detecting a backslip of the rolling material of the rolling stock before the roll gap (4) and triggering at least one control member for adjustment of the flatness of the rolling stock according to the detected backslip.
 6. The method according to claim 5, characterised in that the adjustment of the flatness of the rolling stock is made with additional allowance for flatness measuring signals which represent the flatness of the rolling stock after the roll gap.
 7. The method according to claim 5, characterised in that the backslip of the rolling material of the rolling stock before the roll gap (4) is detected optically or mechanically.
 8. The method according to claim 5, characterised in that the strip tension situation is detected by means of a roller which dips into the strip, attached near the roll gap, for example, an anti-crimping roller.
 9. The method according to claim 8, characterised by two load cells below the mounting of the roller for simultaneously detecting the difference strip tension for adjusting first-order flatness errors (inclination errors) and the global strip tensile stress or strip tensile force at the inlet of the roll mill. 